Criterion Barrels AR15 Ammo Accuracy Comparison

To determine group sizes, Extreme Spread (center to center) and Average to Center measurements were calculated with OnTarget software.

Criterion Barrels has published an interesting Ammo Comparison Test, shooting seven (7) different varieties of .223 Rem ammunition out of an AR15 fitted with Criterion Barrel. Each ammo type was chronographed (10-shot string), then five-shot groups were shot at 100 yards. Along with handloads (69gr Sierra MK + Varget), six (6) types of commercial ammo were tested:

The results are quite interesting. The Federal GMM actually shot the best, beating “untailored” handloads. Basic accurizing efforts and a much better rest set-up showed significant benefits with most ammo types (but not the bulk Wolf Ammo). As you would expect, the more expensive ammo shot best: “Chart 1.2 [below] showcases the average [after accurizing] five round group sizes with each type of ammunition at 100 yards, while Chart 1.3 lists the price per round of each ammunition type. It becomes immediately evident by reviewing these two graphs that there is an inverse relationship between group size and factory ammunition price.”

If you shoot an AR15, or even shoot a .223 Rem bolt gun with factory ammo, you should probably read this test in full. Criterion put a lot of time into the testing, and experimented with a variety of AR options showcased in a series of YouTube videos. SEE: Accurizing the AR-15 Video Playlist.

It’s a fairly easy question to ask, but formulating an educated response can prove to be a very arduous task. While many barrel manufacturers will offer a 1 MOA guarantee with their products, very few explain what this 1 MOA group entails. Is it a three-round group, a five-round group, a 10-round group, or some other pre-determined quantity? Is it fired off of a bench rest, a bipod, or some other fixture? What ammunition should be used in this testing to verify 1 MOA capability?

In our recent “Accurizing the AR-15” video series we outlined a number of internal rifle build variables that come into play when it comes to AR-15 performance. Headspace, component selection, and assembly methods will all have an impact on group sizes.

While external variables such as the shooter and environmental conditions will also play a role in group size, there is one additional internal factor in rifle performance that we have not yet described in detail: Ammunition selection. All other factors considered, poor quality ammunition will likely be a limiting factor in high-performance rifle accuracy.

To put this theory to the test, we sourced six different types of factory ammunition and a hand load previously worked up for a different rifle build. That particular load recipe was not tailored to accommodate this specific rifle barrel. The results of tailoring a hand load to an individual rifle barrel will be outlined in a future article.

Prior to our “Accurizing the AR-15” video series we went about establishing a benchmark for how these seven different loads performed in our rifle build. These “Before” groups were fired off a rifle supported by a Harris bipod featuring a Vortex Viper PST Gen 1 2.5-10×32 FFP through our SPRECCE rifle build.

Improvements made prior to shooting the “After” groups include an optics swap (to a Vortex Viper PST Gen 1 6-24×50 SFP), the addition of an Accu-Wedge, improved fitment during reassembly, and a switch from a bipod to a Sinclair front benchrest assembly and Edgewood rear bag for added stability. Component and assembly details can be found in our recent YouTube video series.

The ammunition selected for this test varies widely in price and quality. Each load utilized in this article was tested with a Magnetospeed V3 chronograph for extreme spread (ES) and standard deviation (SD) over a ten-round course of fire.

Each individual load was also accuracy tested both before and after the rifle was accurized. Accuracy was tested by firing three groups of five rounds with each load from 100 yards, with time allotted to allow the barrel to cool between each string of fire.